that loop was totally bogus.

r->content_type contains no more than one c-t
use ap_field_noparam to strip the decoration and
just a single condition to check the validity of r->content_type


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@100763 13f79535-47bb-0310-9956-ffa450edef68